Ceramics made of sintered body of zirconium oxide (IV) (ZrO2) (referred to as “zirconia” hereinafter) has been used in various fields. The zirconia sintered body having high strength has been applied for a dental prosthetic material, tool, etc., for example. In design of such a zirconia product, change in colors is often required. The zirconia sintered body is used as artificial teeth that are a substitution material in dental treatment, for example. With the artificial teeth, an appearance similar to that of natural teeth is required.
Patent Literature 1 discloses a multi-colored shaped body having layers arranged on top of one another for manufacture of dental restorations. The shaped body disclosed in Patent Literature 1 has (a) at least two successive and differently colored main layers, and (b) at least two differently colored intermediate layers between the at least two successive and differently colored main layers, wherein change in color between the intermediate layers takes place in a direction which is reverse to a direction of the change in color between the main layers.
PATENT LITERATURE 1: JP Patent Kokai Publication No. JP2008-68079A